from django.db import models
from flower.common import ModelBase
from basic_info import models as basic_info_models


class PurchaseOrder(ModelBase):
    """采购单模型（业务模块）"""

    id = models.BigAutoField(primary_key=True)
    merchant = models.ForeignKey(
        basic_info_models.Merchant,
        on_delete=models.PROTECT,
        related_name='purchase_orders',
        verbose_name='所属商户',
    )
    supplier = models.ForeignKey(
        basic_info_models.Supplier,
        on_delete=models.PROTECT,
        related_name='purchase_orders',
        verbose_name='供应商',
    )
    order_date = models.DateField(verbose_name='订单日期')
    total_amount = models.DecimalField(max_digits=15, decimal_places=2, verbose_name='总金额')
    remarks = models.TextField(blank=True, null=True, verbose_name='备注')

    def __str__(self):
        return f'采购订单 {self.id} - {self.supplier.name}'

    class Meta:
        verbose_name = '采购单'
        verbose_name_plural = '采购单'